Lambton OPP say two people suffered significant but non-life threatening injuries after a car and motorcycle collided on Hwy. 402 eastbound on Thursday.
Police say it happened just before noon between London Line and Nauvoo Rd. in Warwick Township.
The investigation has revealed that a passenger car collided with a motorcycle carrying two American passengers.
The motorcycle entered the south ditch, and the two occupants were thrown to the ground.
The motorcyclists were transported to hospital.
The highway was closed for about 30 minutes and the investigation is ongoing.